Process for the regenerative treatment of electrolyte



A ril .14, 1931. -r wm 1,800,457

PROCESS For! THE REGENERATIVE TREATMENT OF ELECTROLYTE Filed Sept. 9, 1927 Copper Tan:

'HTTOENEK Patented Apr. 14', 1931 P TENT oFFIcE TANNIE LEWTN, OF UNIVERSITY CITY, MISSOURI PROCESS FOR THE REGENERATIVE TREATMENT OF ELECTROLYTE :Application filed September 9, 1927. Serial No. 218,491.

This invention relates to certain new and useful process for the regenerative treatment I of electrolyte.

Under date of February 23, 1926, United States Letters Patent No. 1,574,043 were granted me for process for the separation and recovery ofthe copper, tin, and lead content of brass or bronze secondary metals or their residues. Reference is here made to such Letters Patent for a full and complete disclosure and description of said process, which I will herein descriptively designate as the main process. Sufiice it now, for present purposes, to state that, as steps in said main process, the metals or their residues under treatment are cast into forms adapted for use, and then utilized, as anodes in an electrolytic bath in suitable electrolytic tanks, where, y the process of electrolysis, (1) the 0 copper content of such anodes is electrolytically extracted and deposited upon the oathodes, and (2) the tin and lead content or values of such anodes are, through dissolution or disintegration, removed or separated out and deposited and precipitated as slime upon the bottom of the electrolytic cells.

The electrolyte employed in practicing said rocess is of standard composition, comprismg, as its ingredients, as is usual, copper, sulphuric acid, and water in such relative roportions to accomplish and efl'ect the est results.

The actions and results obtained in practicing and carrying on said main process, however, necessarily injuriously or deleteriously afi'ect the strength of the electrolyte for continued use, and it hence becomes neces sary, for the successful operation on a commercial scale of my main process, that the electrolyte be regenerativel treated specifically for (1) the removal 0 the tin and antimony that accumulate therein from the anodes; (2) the replenishment-of its sulphuric acid content, consumed by the lead, tin, and

other ingredients from such anodes; and

(3) thereplenishmentalso of its copper-content, depleted by the cathodes due to the relatively low copper content of the anodes.

, My present invention, therefore, has for its object, and resides in, the provision of an auxiliary or supplemental process whereby the electrolyte may be regeneratively treated, efi'iciently and economically, for continued use in the carrying on, on a successful commercial scale, of my said main process.

To such end and in the present regenerative treatment of the electrolyte, as illustrated in the accompanying diagrammatic or so-called flow drawing, used electrolyte, that is to say,

electrolyte previously employed in practicing C0 or in the carr ing on of the main process, is permitted to ow or circulate .from the elec- I trolytic cells A into a tank or other suitable receptacle B, where such electrolyte is subjected to heat and its temperature thereby raised to a temperature varying between, say, 150 F. and boiling point (212 F.). Such 1 heating eifectively facilitates precipitation of the contained tin and antimony as basic sulphate, and I might here state that while a certain amount of hydrolysis will take place without heating the electrolyte, the precipitation is soon halted on attainment of the hydrolytic equilibriaof the reacting substances, when hydrolysis stops and equilibri um sets in. On the other hand, the hydrolysis of the salts is accelerated and the degree of hydrolysis increases as the temperature rises, the most rapid reaction or precipitation occurring, as I have discovered, when the electrolyte is heated to a temperature of between 185 and 200 F., precipitation taking place i more slowly as the temperature of the electrolyte decreases to 150 F., at which latter temperature precipitation is very slow.

I then add from a tank G to the electrolyte a suitable and required amount of sulphuric acid,.the quantity of which is com mensurate with the former and original sulhuric acid content of the electrolyte and ay vary accordin to the nature and composition of the ano es being treated in practicing my main process.

The temperature of the electrolyte, with its sulphuric acid content restored as described, is maintainedto between and 212 F., and from tank B electrolyte is then passed and circulated through a tank or container D for the addition to the electrolyte of a proper amount or proportion of copper sulphate crystals. Tank D is accordingly suitably provided and equipped with a copper mass E in the form preferably of granules, sheet copper, copper borings, copper turnings, copper clippings, copper Wire, cop per mill scale, copper sludge, or the like, presenting relatively large surfaces for air contact. Such passing and circulating of so partially restored electrolyte through the copper mass is preferably with air contact, and for such purpose I might here state that, to most efl'ectively obtain proper air contact while electrolyte is circulating through the copper mass, the electrolyte is preferably sprayed intermittently, as by means of a suitable pump or other spraying device, E, G, from tank B over and through the copper mass E in tank D, the intermittent spraying being so regulated as to allow and permit sufiicierit time for the air to come in contact with the copper mass, and the so treated electro lyte then circulating through a line or pipe H to a suitable supply-tank J, from whence the regenerated electrolyte again passes or circulates into the electrolytic cells A.

To obviate the addition to the electrolyte being treated of a content of copper sulphate crystals excessive for practicing the particular process of electrolysis to be carried on, preferably but a regulated or controlled part of the electrolyte under treatment is sprayed and circulated throu h tank D. Hence, the tank B also pre erably communicates through pump F and by means of a line or pipe K with the supply-tank J, with which pipe or line K the tank D has valve-controlled communication as by means of a by-pass L.

In such manner, the electrolyte being at the proper temperature, I effect the addition and restoration to the electrolyte of copper sulphate crystals in such amount or quantity to replenish substantially the former and original copper content of the electrolyte for effectively practicing and carrying on my main process.

The regenerated and restored electrolyte is then, as I have stated, passed through from tank J to the electrolytic cells A for re-use in practicing and carrying on my main process.

I am aware that changes in the several steps of my process may be made and substituted for those herein described Without departing from the nature and spirit of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is: 1

That step in the process of purifying and regeneratively treating used electrolyte for employment in the electrolytic removal from brass or bronze secondary metals or their residues of their copper, tin, and lead content, which consists in heating the electrolyte after removal from the electrolytic cell to a name to this specificationi.

TANNIE LEWIN. 

